Crane-supported hooks are widely used for moving heavy loads to or from docks, ship decks, solid land, the sea bottom, and so on. It is of great advantage if, upon "touch down" of the load, the hook will automatically release itself from the load by pushing a cable or shackle out of engagement with the hook, in such a way that it will stay out of engagement for a period of time such as 10 seconds. This is particularly useful when the location of the "touch down" of the load is not easily reached by a person in order to disconnect the hook from the load. Similar problems arise when the load and the place of "touch down" are moving in an uncontrolled manner towards or away from each other, for example from one ship to another ship, from a helicopter, for lowering lifeboats, and so on. By providing immediate release of the load from the hook, there is no danger that the load will be lifted again, and no likelihood of smashing or pounding. The safety aspect of this provision is particularly highlighted when handling bombs, torpedoes, radio equipment, wounded personnel, etc.